Delta-sigma modulator and modulation method, transmission device, and transmission method

A delta-sigma modulation method including:

• generating a pulse phase signal from a phase signal;
• generating a pulse amplitude signal obtained by delta-sigma modulating an amplitude signal with a constant clock;
• delaying, based on the phase signal, the pulse amplitude signal;
• and
• outputting a pulse string obtained by multiplying the delayed pulse amplitude signal by the pulse phase signal.

A transmission device including a signal generator, a delta-sigma modulator, an amplifier, and a band-pass filter, wherein

• the signal generator generates a baseband signal as an input signal,
• the delta-sigma modulator includes:
• a digital baseband circuit that generates an IQ signal from the baseband signal;
• an amplitude-phase conversion men circuit that converts the IQ signal into an amplitude signal and a phase signal;
• a pulse phase signal generation circuit that generates a pulse phase signal from the phase signal;
• a delta-sigma modulation circuit that generates a pulse amplitude signal obtained by delta-sigma modulating the amplitude signal with a constant clock;
• a phase sorting circuit that outputs, based on the phase signal, a control signal;
• a delay switching circuit that delays, based on the control signal, the pulse amplitude signal;
• and
• a mixing circuit that outputs a pulse string obtained by multiplying the delayed pulse amplitude signal by the pulse phase signal,
• the amplifier amplifies the pulse string, and
• the band-pass filter generates an output signal obtained by reconstructing the amplified input signal by passing the amplified pulse string.